This invention relates generally to loading dock shelters and is particularly directed to a deformable, resilient seal for a loading dock shelter.
Trucks or trailers with open rear doorways are typically backed into juxtaposition with a building doorway for loading and unloading. The width of the truck body is typically the same standard width as that of the building doorway. A loading dock shelter is typically disposed about the doorway to seal out the weather during loading and unloading and to provide an effective shelter for men and materials. These loading dock shelters typically include a seal arrangement for providing sealed engagement between the shelter structure and the truck cooperatively engaged therewith.
One type of loading dock shelter commonly in use employs a plurality of dock seals disposed about the sides and top of the building doorway, with each seal employing a compressible body of square or rectangular cross section. To ensure that the rear edges of the truck engage these compressible bodies, the dock seals must be so disposed that they overlap or extend into the truck's doorway. This arrangement has in the past resulted in a reduction in the size of the passageway in limiting access to the truck and has generally inhibited loading and unloading of the truck. An example of this type of loading dock shelter can be found in U.S. Pat. No. 3,375,625. Other examples of loading dock shelters which make use of resilient, yieldable members can be found in U.S. Pat. Nos. 3,638,667, 3,385,001 and 3,500,599.
Compressible pads or seals of the type discussed above also typically require considerable force to be exerted by the truck upon the seal in order to effect sealing engagement therebetween. Even greater compressive forces are typically required at low temperatures because of the more limited compressibility of the pad materials under extreme conditions. Also, when air and water become trapped within the outer cover of this type of seal, the compression and expansion characteristics of the dock seal are reduced, further inhibiting sealed engagement of the truck with the dock seal. The application of large compressive forces by a truck upon the loading dock shelter seal is precluded where the seal is affixed to a relatively lightweight wall such as of sheet metal. Therefore, prior art compression type loading dock shelter seals have been of limited use with relatively lightweight building structures unless such structures are reinforced which frequently is impractical and always increases the cost of the structure.
The present invention is intended to overcome the aforementioned limitations of the prior art by providing a wedge-shaped loading dock shelter seal comprised of a top and a pair of side pads which are oriented inwardly toward a doorway in a wall upon which the pads are mounted. Upon engagement by a truck of the top and side pads and the application of force thereto, the pads flex or bulge outwardly so as to minimize obstruction of an opening in the back of the truck while continuing to engage in a sealed manner the outer, aft periphery of the truck along the top and sides thereof.